﻿LECTURE 
  XXVIII 
  

  

  ARTIFICIAL 
  AND 
  NATURAL 
  SELECTION 
  

  

  The 
  comparison 
  of 
  artificial 
  and 
  natural 
  se- 
  

   lection 
  has 
  furnished 
  material 
  support 
  for 
  the 
  

   theory 
  of 
  descent, 
  and 
  in 
  turn 
  been 
  the 
  object 
  

   of 
  constant 
  criticism 
  since 
  the 
  time 
  of 
  Darwin. 
  

   The 
  criticisms, 
  in 
  greater 
  part, 
  have 
  arisen 
  

   chiefly 
  from 
  an 
  imperfect 
  knowledge 
  of 
  both 
  

   processes. 
  By 
  the 
  aid 
  of 
  distinctions 
  recently 
  

   made 
  possible, 
  the 
  contrast 
  between 
  elementary 
  

   species 
  and 
  improved 
  races 
  has 
  become 
  much 
  

   more 
  vivid, 
  and 
  promises 
  to 
  yield 
  better 
  results 
  

   on 
  which 
  to 
  base 
  comparisons 
  of 
  artificial 
  and 
  

   natural 
  selection. 
  

  

  Elementary 
  species, 
  as 
  we 
  have 
  seen 
  in 
  

   earlier 
  lectures, 
  occur 
  in 
  wild 
  and 
  in 
  culti- 
  

   vated 
  plants. 
  In 
  older 
  genera 
  and 
  systematic 
  

   species 
  they 
  are 
  often 
  present 
  in 
  small 
  numbers 
  

   only, 
  but 
  many 
  of 
  the 
  more 
  recent 
  wild 
  types 
  

   and 
  also 
  many 
  of 
  the 
  cultivated 
  forms 
  

   are 
  very 
  rich 
  in 
  this 
  respect. 
  In 
  agriculture 
  

   the 
  choice 
  of 
  the 
  most 
  adequate 
  elementary 
  

   forms 
  for 
  any 
  special 
  purpose 
  is 
  ac- 
  

  

  798 
  

  

  